This application is related to U.S. Ser. No. 08/617,690 entitled "A New Lock-I/O Command," filed Mar. 19, 1996, and incorporated herein by reference.
The invention relates generally to protocols for performing I/O between a host computer and a peripheral, such as a data storage system.
Data storage devices for use with computers have range in complexity from relatively simple, single disk arrangements to very sophisticated, intelligent data storage systems that include arrays of multiple disks and that are capable of storing many tera bytes of data. For any of these storage devices, some protocol must be provided for handling communications and I/O between the host computer and the device.
The storage device manufacturers tend to use an existing, standards-based interface for handling the communications and I/O between the host computer and their devices. One such interface commonly used is the SCSI interface. One main advantage of using such a standards-based interface is that many other vendors and manufacturers also use and support it. Thus, customers to whom a manufacturer wants to sell its storage products are already familiar with the interface and indeed are likely to already be using it. However, whatever benefits are associated with adopting a standard interface often come with a cost that is not simply monetary. More specifically, such standards-based interfaces frequently impose limitations on the overall system performance that can be achieved. That is, they may not be optimized for specific devise architectures or uses.